Master selector switch



y 1961 E. F. REIHMAN ETAL 2,991,337

MASTER SELECTOR SWITCH Filed Sept. 2, 1958 f77/9/7/0/19 @AW/d tfss/ya/zr/F Ba /i075 I 4/? f g 7Z6 Af/af/fg/ United States Patent assignors toGeneral Electric Company, a corporation of New York Filed Sept. 2, 1958,Ser. No. 758,340 2 Claims. (Cl. 20011) The present invention relates toan electrical switch and particularly a master switch for controlling aplurality of circuits with two separate On and Off knobs that permitone-hand operation.

This switch has been designed especially for a remotecontrol wiringsystem where the switching of the power circuits is accomplished bymeans of low voltage control circuits using relays installed directly inthe outlet box of the circuit that is being controlled or alternatelygrouped in special gang boxes to obtain zoned installation near theservice entrance box. These relays are actuated by a 24 volt circuitsupplied by means of a special energy-limiting transformer andcontrolled by low voltage switches which are single pole, double throw,momentary contact, normally operr type switches. Since these switchesare of the momentary contact type, any number can be placed in parallelfor multipoint control. This eliminates the need for special switchessuch as three-way and four-way switches as required in the ordinarywiring system.

The master selector switch of this invention as presently used is atwelve position selector switch having both an On and an Off knobwhereby any one of the twelve circuits may either be individuallycontrolled or operated in unison with a sweep of the knob or knobs. Bothknobs act in a similar manner. The On knob, for example, may be turnedto register with a specific numbered position indicated on the faceplateof the switch. The knob is then depressed to energize the lightingfixture of that particular circuit. Alternatively, the knob may bedepressed and then turned to sweep the fixed contacts of the switch andenergize the circuits in unison.

This master selector switch replaces a combination switch having arotary switch and a rocker type switch, where the rotary switch selectsthe circuit or circuits and the rocker type switch either energizes orde energizes these particular circuits. However, this former type switchrequired the use of both hands; one hand for operating each switch. Thisinvention has simplified :the operation of a master selector switch byrequiring the use of only one hand in accomplishing the switchingoperation.

The principal object of this invention is to provide a rotary selectorswitch with a novel indexing arrangement that operates in both theextended and depressed positions of the switch knob.

A further object of this invention is to provide a master selectorswitch for controlling a plurality of circuits by utilizing two similarrotary switches in a single housing where the circuits may either becontrolled individually or in unison.

A further object of this invention is to provide a master selectorswitch with an illuminated faceplate having several windows provided inthe faceplate so that the circuits may be identified by printed slips ofpaper mounted in the windows, thereby furnishing a directory for thewiring system.

A still further object of this invention is to provide an illuminatedfaceplate with a light dimmer control that permits adjusting the lightin a limited range of brightness.

The preferred embodiment of this invention includes a switch housingformed by a recessed base member and a metal cover plate. The base has aseries of fixed congame ICC

tacts arcuately arranged around the longitudinal axis of the shaft ofthe knob or handle of the switch. This shaft is mounted for slidingmovement within the base and extends through the metal cover plate forreceiving a knob. It will be understood that this master selector switchincorporates two similar switches, although for the sake of brevity onlyone will be discussed in detail. Fixedly mounted on the shaft is amovable contact blade. One end of the contact blade includes a detentarm that extends into a well within the base and is adapted to engage aseries of notches formed in the side walls of the well for indexing thecontact blade into positions overlying the fixed contacts of the switch.Spring means are provided to hold the shaft and, hence, the contactblade normally in an extended position where the contact blade will beout of engagement with the fixed contacts. The switch knob may bedepressed to compress the spring and close the circuit between themovable and fixed contacts. This may be done to activate a singlecircuit or the knob may be turned while it is depressed to sweep thefixed contacts and energize all of the circuits in unison.

The faceplate of this selector switch incorporates printed tabs whichare selected to identify the circuit for each numbered position of theknobs. Accordingly, the operator is aware of the exact identification ofeach circuit so that pin-point control can be effected with accuracy.Moreover, the faceplate has been illuminated in a novel manner byincorporating a transparent plate with an opaque finish on its back sideand inserting a light source into a small dome-shaped formation visibleon the front side of the plate. A small lamp is inserted into the domethrough the back of the plate to light up the face of the plate. Also, aportion of the light rays travels in the plane of the plate and isemitted at sev eral strategic locations adjacent the indicia on theplate as well as the directory for identifying the various circuits,

Our invention will be better understood from the following descriptiontaken in connection with the accompanying drawingand its scope will bepointed out in the appended claims.

FIGURE 1 is a front view of a master selector switch embodying thepresent invention with the right half of the faceplate removed forobserving the adjusting means for the dimmer control of the light sourceof the faceplate.

FIGURE 2 is an isometric view of the dimmer control arm of FIGURE 1.

FIGURE 3 is a detailed showing of the fastening means for the dimmer armon the metal cover plate of the switch.

FIGURE 4 is an exploded view of a portion of the switch showing theinterior of the recessed base, the shaft of the switch handle having amovable contact blade mounted thereon for cooperation with a coiledspring that normally holds the shaft in an extended position.

FIGURE 5 is a cross-sectional side elevational view taken on the line 55of FIGURE 1 through the shaft of the right-hand knob of the switch.

FIGURE 6 is an enlarged cross-sectional view of the transparentfaceplate showing a layer of opaque paint on its back surface.

Referring in detail to FIGURES 1 and 5 of the drawing, numeral 15identifies a switch housing formed by a recessed base member 16 and ametal cover plate 17. A tapped opening 18 is provided at each side ofthe cover plate 17 for receiving a fastening screw (not shown) thatextends through a decorative faceplate 19 for holding the faceplate overthe switch housing.

Turning first to a consideration of the switch mechanism, reference willbe made to FIGURES 4 and 5 of the drawing. In FIGURE 4, the recessedbase member 16 is shown in isometric view. The base is a moldedinsulating part of box-like construct-ion with a bottom wall 20 andopposite pairs of side walls 21 and 22. The side opposite the bottomwall 2%) is open for receiving the switch parts therethrough. Asmentioned previously, the master selector switch of this inventionincorporates. two similar switch structures. One switch controls the Oncoils of a group of relays while the second switch controls the Offcoils of the same group of relays. Because of the duplication of theswitch elements, only one switch construction will be described indetail, although it should be recognized that when speaking of oneswitch, the other switch is also included.

As best seen in FIGURE 5, the bottom wall 20 of the switch base has anenlargement 23 extending rearwardly therefrom. The center of thisenlargement contains a cylindrical cavity 24- for receiving theinnermost end of a shaft 25 for the switch handle 26. Centered aroundthe bore 24 are a group of twelve fixed contacts 27. As seen in FIGURE5, each contact 27 is in the shape of a pin having a rounded head 28 anda shank portion 29 that extends through the bottom wall 20 of the baseand has soldered to its end a flexible lead wire 30. A spring contactblade 31 is staked onto the mid-portion of the shaft 25. When theinnermost end of the shaft 25 is positioned in the bore 24 of the base,the spring blade 31 represents the movable contact of the switch and iscapable of making electrical connection between each of the fixedcontacts 27 and the grounded plate 17. A good electrical connection ismade between the shaft 25 and cover plate 17 by a straight wire spring36 as seen in FIGURE 1. This spring is confined at its ends by a pair oflancings 3-7 struck from the plate 17 so that the mid-portion of thespring is tensioned against one side of the shaft.

A coiled spring 32 is assembled over the innermost end of the shaft 25and is seated on the bottom wall 20 of the switch base. This springnormally holds the shaft in an extended position outwardly from theswitch housing. In this position the movable contact blade 31 is out ofengagement with the fixed contact 27, as seen in FIGURE 5. The circuitor circuits may be closed by first dialing the handle 26 until a desiredcircuit position is obtained and then pushing against the handle againstthe action of the spring 32 to slide the shaft inwardly and close thecontacts. Alternatively, the handle may be first depressed and thenturned to sweep the movable contact blade over the fixed contacts sothat all of the circuits will be closed in unison. The depth of the bore24 is such that the shaft 25 will bottom in the bore as the handle isdepressed. This prevents undue stress being exerted on the springcontact arm 31.

It is necessary to provide means for indexing the movable contact bladeso that it may be positioned accurately over each fixed contact 27, andlikewise to provide a certain amount of snap action as the movable bladeis shifted from one position to another. This important element of theinvention is represented by a detent arm 33 that is an integral part ofthe movable blade 31 and extends at substantially a right angle thereto.A deep well 34 is formed in the enlargement 23 of the baseconcentrically with the bore 24. This well is for accommodating thedetent arm 33. A series of notches or flutes 35 are arranged on the sidewalls of the well 34 and are engageable by the free end of the detentarm 33. These notches or flutes 35 are elongated so that the detent armwill be in contact therewith in either the extended or depressedpositions of the switch handle. The detent arm 33 must be relativelystiff for the best performance. Since the contact arm 31 is made of thesame sheet stock as the detent arm, the contact arm is made resilient byforming a hole 31 in its midportion.

As mentioned previously, the switch includes a faceplate 19 oftransparent plastic material which is assembled behind the two switchhandles 26 and over the switch housing '15. The front surface of theplate 19 is recessed as at 40 directly behind the switch handles toaccommodate the sliding movement of the handle inwardly toward a circuitclosing position. When the handle is in its extended position, its backside will be substantially flush with the front surface of the plate 19,as seen in FIGURE 5. Suitable indicia 41 are provided on the platearound the periphery of each switch handle so that the various circuitpositions of the switch may be identified. For instance, twelve numeralsare shown, indicating that the switch is a l2-position switch. Thenumerals and other desired indicia are molded in relief on the back sideof the faceplate 19. The indicia are first covered with a dark paint 7t?such as brown. Then a lighter tone of ivory colored paint 71, shown inFIGURE 6, is applied over the back surface which gives the plate aglass-like appearance with a good contrasting coloring. The wall plate19 also includes a directory at the top portion of the plate comprisinga series of transparent unpainted windows 42, one for each circuit, sothat small printed tabs may be pasted in the windows for identifying thedifferent circuits as to the location of the lighting fixtures, outlets,etc. that may be controlled by this master selector switch. Each window42 is marked with a numeral corresponding with the numerals centeredaround the switch handles.

Since this master selector switch serves as the control means for aplurality of individual circuits, it is necessary that the operator beable to read the directory at the top of the faceplate as well as todistinguish between the numerals 41 around each switch handle.Accordingly, the faceplate has been illuminated by a small lamp 45 thatextends through the back of the plate into a hollow dome-like formation46 that projects from the front equidistant from the two handles andraised slightly above them. The lamp is a 37 /2 volt lamp that will beused in a circuit delivering a maximum of 30 volts which should increasethe life of the lamp to a point where it should never have to bereplaced. The major portion of the inner surface of the dome 46 is alsocovered with an opaque paint, but a transparent ring 47 near the base ofthe dome is left free of paint so that the light emitted by the lamp 45may shine over the entire front surface of the plate. The light waveswill also travel in the plane of the plate 19 and be emitted out alongthe edges of the recesses 40 and the windows 42, as seen in FIG- URE 5.

As seen in FIGURE 5, the lamp 45 is supported in a bayonet socket 48that is molded integrally with the side wall 22 of the base. The lamp 45has a bayonet base 49 which is received in the socket 48 with its twobayonet slots 50, as seen in FIGURE 4. The center contact of the lampsocket is represented by a spring blade 51 that is fastened at one endto the back side of the socket while its opposite end overlies theopening in the socket for making engagement with the center contact ofthe lamp. A lead wire 52 is soldered or otherwise fastened to thecontact strip 51 for connecting the lamp in an operating circuit. Theside grounding contact of the lamp socket 48 is in the form of a verythin metal strip 53 that is fastened at one end to the metal mountingstrap 17, as at 54 in FIGURE 5. This side contact 53 is carried by themetal strap and is of very thin sheet stock so that the free end of thestrip may be loosely inserted into the lamp socket 48. Then when thelamp 45 is inserted into the socket, the strip will be shaped to conformto the side walls of the socket. At the same time the strip will haveenough spring action that it will make good electrical contact with thelamp base. The end 54 of the side contact 53 is insulated from the metalstrap 17 by a fiber bushing 55. A metal eyelet holds the side contact 53onto the strap 17 but the eyelet is also insulated from the strap by thebushing. This eyelet is shown as element 56 in FIGURE 1 and itcooperates with an uninsulated eyelet 57 in holding a thin resistorstrip 58 onto t e front side of the strap 17. This resistor strip isinsulated from the strap but it is electrically connected to the twometal eyelets 5'6 and 57'. The purpose of this resistor strip 56 is toprovide a dimming control for the lamp 45 by means of an adjustabledimmer arm 59 that is pivotally connected to the strap 17. Stop members69 are formed on the strap 17 to limit the extent of turning of thedimmer arm. Finally, the metal strap 17 is joined as a part of thecircuit of the switch by attaching a lead wire 60 to a metal eyelet 61that fastens the strap 17 to the base 16. Accordingly, the severalcircuits through the switch are carried by the lead wires 30 through thefixed contacts 27 and movable contact blade 31, through the shaft 25 andwiping spring 36 to the strap 17 and then through the neutral wire 60.As for the lighting circuit for the switch, there is the lead wire 52for the lamp socket 48 with its center contact 51 and side groundingcontact 53 joined to the variable resistor strip 58 and through thedimmer arm 59 to the metal strap 17 and from there to the neutral wire60.

The adjustable dimmer arm 59 is provided with a novel pivotal end 65that may be engaged by a screwdriver for turning the arm to obtain adesired degree of brilliance. Looking at FIGURES l-3, the pivotal end 65of the dimmer arm is provided with four radially-spaced lancings 66which are raised on the underside of the arm and establish across-shaped slot 67 in the arm, as best seen in FIGURE 1. Theselancings 66 are adapted to extend through a circular opening 68 in thestrap 17 and be formed outwardly to engage the back side of the strapand prevent the separation of the arm from the strap. These lancingsprovide a fastening means between the arm and the strap and likewiseestablish a cross-shaped slot 67 for receiving the blade of ascrewdriver for ease in adjusting the position of the arm on theresistor strip 58. A suitable circular opening (not shown) is providedin the faceplate 19 under the right-hand switch handle 26 so that ascrewdriver may extend therethrough and engage in the slot 67, aspreviously mentioned.

Having described above our invention of a novel master selector switchwith an illuminated faceplate, it will be readily apparent to thoseskilled in this art that we have facilitated the ease of controlling aplurality of circuits in such systems as a low voltage remote controlwiring system, and that we have provided a switch mechanism with areliable detent mechanism for all positions of the switch handle. Thefaceplate has been illuminated in a novel manner, making it easy to viewthe positions of the switch handles as well as providing a directory atthe top portion of the faceplate.

Modifications of this invention will occur to those skilled in this artand it is to be understood, therefore, that this invention is notlimited to the particular embodiments disclosed but that it is intendedto cover all modifications within the true spirit and scope of thisinvention as claimed.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

l. A master selector switch comprising a switch housing formed by arecessed base member of insulating material and a metal cover plate, theplate being connected to the grounded side of the switch circuit, ashaft in said housing capable of turning movement about its longitudinalaxis extending through an opening in said cover plate and being slidablysupported by said base, a spring normally holding said shaft in anextended position, a series of fixed contacts arranged in the housingand centered around the shaft, a movable contact blade of springmaterial fixed on said shaft and having two opposite arms, one arm beinga contact arm for engagement with the fixed contacts and the other armbeing a detent arm, the said contact arm being out of engagement withthe fixed contacts when the shaft is in its extended position, thehousing including a well for receiving the said detent arm, the sidewalls of the Well having a series of notches that are engaged by thedetent arm of the contact blade as the shaft is turned, and a springmember supported by the said plate and bearing against the side of saidshaft for maintaining good electrical connection between said shaft andsaid plate.

2. A master selector switch as recited in claim 1 wherein the saidspring member is a bowed spring that is held at its ends and tensionedat its mid-portion against one side of said shaft.

References Cited in the file of this patent UNITED STATES PATENTS1,110,027 Aitken Sept. 8, 1914 1,927,301 Weichelt Sept. 19, 19332,575,820 Linton Nov. 20, 1951 2,580,056 Wheeler Dec. 25, 1951 2,650,270Mucher Aug. 25, 1953 2,703,346 Sawyer Mar. 1, 1955 2,734,976 Strege Feb.14, 1956 FOREIGN PATENTS 377,574 Germany June 22, 1923 580,803 FranceSept. 11, 1924

